From: Nikolay Aleksandrov <nikolay@cumulusnetworks•com>
To: Xin Long <lucien.xin@gmail•com>
Cc: network dev <netdev@vger•kernel.org>, davem <davem@davemloft•net>,
Hannes Frederic Sowa <hannes@stressinduktion•org>
Subject: Re: [PATCH net] bridge: a netlink notification should be sent whenever those attributes change
Date: Sat, 5 Mar 2016 20:43:07 +0100 [thread overview]
Message-ID: <56DB36CB.2010407@cumulusnetworks.com> (raw)
In-Reply-To: <CADvbK_eiSQFT9uKfJZf_8omcFyiVuh+XbnywzC2wszxqPuThjQ@mail.gmail.com>
On 03/05/2016 03:44 PM, Xin Long wrote:
> On Thu, Mar 3, 2016 at 8:29 PM, Nikolay Aleksandrov
> <nikolay@cumulusnetworks•com> wrote:
>>
>> This is incorrect because you don't have rtnl here, bridge device sysfs
>> options take care of rtnl only on per-option basis and they obtain and
>> release it themselves, so you won't have rtnl held when you call
>> netdev_state_change. While I agree that this is needed, a larger change
>> would be necessary for br_sysfs_br.c.
> Sorry, I can't follow you, cause I didn't see any held in dev_ioctl, like:
> ipip6_tunnel_ioctl
> ipip6_tunnel_update
> netdev_state_change
>
> why sysfs have to hold rtnl ?
>
See the comment above dev_ifsioc:
/*
* Perform the SIOCxIFxxx calls, inside rtnl_lock()
*/
static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd)
{
...
it is usually called like:
rtnl_lock();
ret = dev_ifsioc(net, &ifr, cmd);
rtnl_unlock();
And also you cannot be calling netdevice notifiers without RTNL. So in any
case you do need it here as well, in fact you'll surely hit the ASSERT_RTNL();
in call_netdevice_notifiers_info if you do so, thus I'm not sure how this
patch was actually tested.
>> Off-topic: I've been looking into factoring out the bond option API and reusing
>> it here as it already has all of this handled, but I won't have time to finish
>> it before the next merge window, so if you fix the issue here I'm okay with
>> this as interim solution.
>>
>> Cheers,
>> Nik
>>
next prev parent reply other threads:[~2016-03-05 19:43 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-03 12:16 [PATCH net] bridge: a netlink notification should be sent whenever those attributes change Xin Long
2016-03-03 12:29 ` Nikolay Aleksandrov
2016-03-05 14:44 ` Xin Long
2016-03-05 19:43 ` Nikolay Aleksandrov [this message]
2016-03-06 6:08 ` Xin Long
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=56DB36CB.2010407@cumulusnetworks.com \
--to=nikolay@cumulusnetworks$(echo .)com \
--cc=davem@davemloft$(echo .)net \
--cc=hannes@stressinduktion$(echo .)org \
--cc=lucien.xin@gmail$(echo .)com \
--cc=netdev@vger$(echo .)kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox